Ingredients
2 tablespoons olive oil
8 ounces shiitake mushrooms, stems discarded, caps thinly sliced
Coarse salt and ground pepper
10 ounces baby spinach (7 cups)
1 to 2 teaspoons white-wine vinegar
Preparation
In a large skillet, heat 1 tablespoon oil over medium. Add mushrooms; season with salt and pepper. Cook, stirring occasionally, until browned, 8 to 10 minutes. Transfer to a plate (reserve skillet).
Heat remaining tablespoon oil in skillet. Add as much spinach as will fit; season with salt and pepper. Toss spinach, adding more to skillet as room becomes available. Cook until tender, about 2 minutes. Remove from heat, drain off any excess liquid, and stir in vinegar. Top spinach with mushrooms.
